Maintainable models and topology
Blender is not the best tool to use for procedural modeling workflow. Its workflow is quite destructive actually. There are better tools like Modo's MeshFusion, Houdini or Moi3D if you value procedurality.

It is possible to create the shapes parametrically and mesh them with clever math, there are some auto-retopology tools out there, but humans can do usually better than that. Maybe in couple of years there will be AI to do that well for us.

Since the workflow is destructive it's important to finalize the design before modeling. That's what concept art, sketches and 2D studies are for. There is some room for experimentation in modeling phase, but it should be well defined beforehand.